The present invention relates to absorbent articles.
A various assortment of absorbent articles of the disposable type, such as diapers and sanitary pads, have been proposed which are discarded after a single use. Several factors are of importance in determining whether such articles will be acceptable to the consumer. The articles should rapidly receive and dissipate body fluids without a significant amount of backwetting to the wearer's skin and without wicking and leakage from the article, while providing comfort to the wearer. Such absorbent articles also should be available to the consumer at a relatively low cost, since they are not reused.
Much of the cost and deficiencies in prior articles may be attributed to the strucutre of and the materials used in the articles. In the case of disposable diapers, structures are often provided having an absorbent pad, a fluid impervious backing sheet covering a back surface of the pad, and a fluid pervious top sheet covering a front surface of the pad. Particularly in the case where the absorbent pads are made of a mass of fibers, such as comminuted wood pulp, an absorbent wadding sheet is often placed over the front surface of the pad to maintain structural integrity of the pad when wet. In addition to adding to the cost of the diapers, such top wadding sheets impair the function of the diaper in a number of respects. The wadding sheets impede the rapidity of fluid passage from the top sheet into the pad, and retain fluid adjacent the front surface of the diaper, thus increasing the amount of backwetting from the diaper to the infant. The wadding sheet also adds stiffness to the diaper, thus decreasing the amount of comfort the diaper provides for the infant.
In the past, the top sheet of the diaper, which is usually made of nonwoven material, has been made relatively thick and strong to prevent breaking up of the top sheet when it becomes wet during use. The relatively heavy top sheet utilized in prior diapers also adds significantly to the cost of the diaper. Accordingly, it is desirable to reduce the thickness of the top sheet altogether. Whether or not the top sheet is totally eliminated from the diaper, it is necessary to provide a comfortable surface of the diaper for the infant.